BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
View EA class & enroll
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

715+ score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

GMAT Prep Exam

Expert replies
by janvierek » Wed Jun 20, 2007 7:33 pm
Can anyone explain to me how to do the following questions?

1.The function f is defined for all positive integers n by the following rule:f(n) is the number of positive integers each of which is less than n and has no positive factor in common with n other than 1. if p is any prime number then f(p) =

a)p-1
b)p-2
c)p+1/2
d)p-1/2
e)2


2. A thin piece of wire 40 meters long is cut into 2 pieces. One piece is used to form a circle with radius r and the other is used to form a square, no wire is left over. Which of the following represents the total area in square meters of the circular and the square regions in terms of r

a)IIr sq
b)IIr sq +10
c)II r sq + 1/4 II sq r sq
d)IIr sq + (40-2IIr) sq
e)IIs sq +(10- 1/2IIr) sq


3. A vending machine is designed to dispense a ounces of coffee into a cup. after a test that recorded the number of ounce of coffee in each of 1000 cups dispensed by the vending machine the 12 listed amounts below, in ounces were selected from the data. If the 1000 recorded amounts have a mean of 8.1 ounces and standard deviation of 0.3 ounce, how many of the 12 listed amounts are within 1.5 standard deviation of the mean?
7.51 8.22 7.86 8.36
8.09 7.83 8.30 8.01
7.73 8.25 7.96 8.53

a) four
b) six
c)nine
d)ten
e)eleven
Join the discussion
Source: — Problem Solving |

Re: GMAT Prep Exam

by jayhawk2001 » Wed Jun 20, 2007 9:14 pm
janvierek wrote:Can anyone explain to me how to do the following questions?

1.The function f is defined for all positive integers n by the following rule:f(n) is the number of positive integers each of which is less than n and has no positive factor in common with n other than 1. if p is any prime number then f(p) =

a)p-1
b)p-2
c)p+1/2
d)p-1/2
e)2
Take n = 5. The positive integers that are less than 5 and that have
no positive factor in common with 5 are 1, 2, 3 and 4.

For a prime number p, we know there are 1 ... p-1 are the numbers
that don't have a factor in common with p. So, f(p) = p-1.

janvierek wrote:
2. A thin piece of wire 40 meters long is cut into 2 pieces. One piece is used to form a circle with radius r and the other is used to form a square, no wire is left over. Which of the following represents the total area in square meters of the circular and the square regions in terms of r

a)IIr sq
b)IIr sq +10
c)II r sq + 1/4 II sq r sq
d)IIr sq + (40-2IIr) sq
e)IIs sq +(10- 1/2IIr) sq
Circle with radius r will have a perimeter of 2*pi*r. The rest i.e. 40-2*pi*r
will be the perimeter of the square.

Side of the square = (40-2*pi*r) / 4 = 10-pi*r/2

So, total area pi*r^2 + (10-pi*r/2)^2

janvierek wrote:
3. A vending machine is designed to dispense a ounces of coffee into a cup. after a test that recorded the number of ounce of coffee in each of 1000 cups dispensed by the vending machine the 12 listed amounts below, in ounces were selected from the data. If the 1000 recorded amounts have a mean of 8.1 ounces and standard deviation of 0.3 ounce, how many of the 12 listed amounts are within 1.5 standard deviation of the mean?
7.51 8.22 7.86 8.36
8.09 7.83 8.30 8.01
7.73 8.25 7.96 8.53

a) four
b) six
c)nine
d)ten
e)eleven
1.5 standard deviations = 1.5 * .3 = .45

1.5 sd from the mean (+ve) = 8.1 + 0.45 = 8.55
1.5 sd from the mean (-ve) = 8.1 - 0.45 = 7.65

Find the values which are in the range 7.65 - 8.55 from the list
and you have the answer...
Join the discussion

GMAT Prep Exam

by janvierek » Thu Jun 21, 2007 1:32 pm
Thank for your help. However i still don't get how you got p-1. i do understand the first part (Take n = 5. The positive integers that are less than 5 and that have no positive factor in common with 5 are 1, 2, 3 and 4)
could you please explain to me how you got p-1?
thanks

1.The function f is defined for all positive integers n by the following rule:f(n) is the number of positive integers each of which is less than n and has no positive factor in common with n other than 1. if p is any prime number then f(p) =

a)p-1
b)p-2
c)p+1/2
d)p-1/2
e)2
Join the discussion

by givemeanid » Thu Jul 26, 2007 6:20 am
Anonymous wrote:Jayhawk.... why did you multiply .3 * 1.5 for question #2

Std dev measure how far data is from mean. Let the mean = m and std dev = s. A value that is one std dev away from the mean has to lie between (m-s) and (m+s). Similary, a value that is 2 std dev away will lie between (m-2s) and (m+2s).
So It Goes
Join the discussion